Control Station, Mobile Station, Mobile Communication System and Mobile Communication Method

1. A User Equipment (UE) in a mobile communication system that comprises a Packet data Gateway (PGW) and the UE, the UE comprising: control circuitry configured to establish a first transfer path by way of a first access network between the UE and the PGW, wherein when performing transmission/reception of a plurality of flows with the PGW by using the first transfer path, the control circuitry is configured to establish a default Evolved Packet System (EPS) bearer as a second transfer path by way of a second access network between the UE and the PGW by transmitting an attach request for starting an attach procedure, and the control circuitry is configured to establish a specific EPS bearer as a third transfer path by way of the second access network between the UE and the PGW after transmitting a notice including identification information that identifies a specific flow among the plurality of flows, to a core network by way of the second access network, wherein the control circuitry is configured to switch a transfer path for performing transmission/reception of the specific flow to the third transfer path by way of the second access network.

2. A Packet data Gateway (PGW) in a mobile communication system that comprises the PGW and a User Equipment (UE), the PGW comprising: control circuitry configured to establish a first transfer path by way of a first access network between the UE and the PGW, wherein when performing transmission/reception of a plurality of flows with the UE by using the first transfer path, the control circuitry is configured to establish a default Evolved Packet System (EPS) bearer as a second transfer path by way of a second access network between the UE and the PGW in accordance with transmission of an attach request from the UE for starting an attach procedure, and the control circuitry is configured to establish a specific EPS bearer as a third transfer path by way of the second access network between the UE and the PGW after receiving a notice including identification information that identifies a specific flow among the plurality of flows, by way of the second access network, wherein the control circuitry is configured to switch a transfer path for performing transmission/reception of the specific flow to the third transfer path by way of the second access network.

3. A mobile communication system comprising: a Packet data Gateway (PGW); and a User Equipment (UE), wherein the PGW and the UE are configured to establish a first transfer path by way of a first access network between the UE and the PGW, when performing transmission/reception of a plurality of flows by using the first transfer path, the UE and the PGW are configured to establish a default Evolved Packet System (EPS) bearer as a second transfer path by way of a second access network between the UE and the PGW by transmitting an attach request of the UE for starting an attach procedure, the UE is configured to establish a specific EPS bearer as a third transfer path by way of the second access network between the UE and the PGW after transmitting a notice including identification information that identifies a specific flow among the plurality of flows, to a core network by way of the second access network, and the UE and the PGW are configured to switch a transfer path for performing transmission/reception of the specific flow to the third transfer path by way of the second access network.

4. A communication method for a User Equipment (UE) in a mobile communication system that includes a Packet data Gateway (PGW) and the UE, the method comprising: establishing, in the UE, a first transfer path by way of a first access network between the UE and the PGW; when performing transmission/reception of a plurality of flows with the PGW by using the first transfer path, establishing a default Evolved Packet System (EPS) bearer as a second transfer path by way of a second access network between the UE and the PGW by transmitting an attach request for starting an attach procedure; establishing a specific EPS bearer as a third transfer path by way of the second access network between the UE and the PGW after transmitting a notice including identification information that identifies a specific flow among the plurality of flows, to a core network by way of the second access network; and switching a transfer path for performing transmission/reception of the specific flow to the third transfer path by way of the second access network.

5. A communication method for a Packet data Gateway (PGW) in a mobile communication system that comprises the PGW and a User Equipment (UE), the method comprising: establishing, in the PGW, a first transfer path by way of a first access network between the UE and the PGW; when performing transmission/reception of a plurality of flows with the UE by using the first transfer path, establishing a default Evolved Packet System (EPS) bearer as a second transfer path by way of a second access network between the UE and the PGW in accordance with transmission of an attach request from the UE for starting an attach procedure; establishing a specific EPS bearer as a third transfer path by way of the second access network between the UE and the PGW after receiving a notice including identification information that identifies a specific flow among the plurality of flows, by way of the second access network; and switching a transfer path for performing transmission/reception of the specific flow to the third transfer path by way of the second access network.

6. A communication method for a mobile communication system which comprising a Packet data Gateway (PGW) and a User Equipment (UE), the method comprising: establishing a first transfer path by way of a first access network between the UE and the PGW; when performing transmission/reception of a plurality of flows by using the first transfer path, establishing a default Evolved Packet System (EPS) bearer as a second transfer path by way of a second access network between the UE and the PGW in accordance with transmission of an attach request of the UE for starting an attach procedure; establishing a specific EPS bearer as a third transfer path by way of the second access network between the UE and the PGW after transmitting a notice including identification information that identifies a specific flow among the plurality of flows, to a core network by way of the second access network; and switching a transfer path for performing transmission/reception of the specific flow to the third transfer path by way of the second access network.

7. A core network in a mobile communication system that comprises a Packet data Gateway (PGW) and a User Equipment (UE), the core network comprising: control circuitry configured to establish a first transfer path by way of a first access network between the UE and the PGW, wherein when performing transmission/reception of a plurality of flows with the UE by using the first transfer path, the control circuitry is configured to establish a default Evolved Packet System (EPS) bearer as a second transfer path by way of a second access network between the UE and the PGW in accordance with transmission of an attach request from the UE for starting an attach procedure, and the control circuitry configured to establish a specific EPS bearer as a third transfer path by way of the second access network between the UE and the PGW after receiving a notice including identification information that identifies a specific flow among the plurality of flows, from the UE by way of the second access network, wherein the control circuitry is configured to switch a transfer path for performing transmission/reception of the specific flow to the third transfer path by way of the second access network.

8. A communication method for a core network in a mobile communication system that comprises a Packet data Gateway (PGW) and a User Equipment (UE), the communication method comprising: establishing, in the PGW, a first transfer path by way of a first access network between the UE and the PGW; when performing transmission/reception of a plurality of flows with the UE by using the first transfer path, establishing a default Evolved Packet System (EPS) bearer as a second transfer path by way of a second access network between the UE and the PGW in accordance with transmission of an attach request from the UE for starting an attach procedure; establishing a specific EPS bearer as a third transfer path by way of the second access network between the UE and the PGW after receiving a notice including identification information that identifies a specific flow among the plurality of flows, from the UE by way of the second access network; and switching a transfer path for performing transmission/reception of the specific flow to the third transfer path by way of the second access network.